Efferent stimulation maximally suppresses basilar membrane vibration near the characteristic frequency

Evidence

In contrast, the slow efferent effect (Sridhar et al. 1997 ) can cause a constant Ca2+ release from OHC internal stores, the lateral cisternae, while CAS is on. We hypothesize that this constant influx of Ca2+ may help to accelerate Ca2+ -dependent Ca2+ -uptake and thus, a quicker recovery of the system. In summary, the current experiments reveal a pronounced effect of LF exposure on the active mechanisms in the inner ear, as they are mediated by OHCs. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3744 (#expands, via linked claim)

The function of the outer hair cells is less well known, but they do not transmit information to the brain because they are connected to neurons that send information from the brain. It is believed that the outer hair cells affect the way the basilar membrane vibrates such that there is local amplification of the movement when that place is being stimulated acoustically. When they are stimulated via the neurons from the brain, it has been shown that the length of the outer hair stereocilia change (Hakizimana et al., 2012). This has the effect of mechanically amplifying the basilar membrane response within an auditory filter. Plack (2005) suggests that this amplifies frequencies perhaps half an octave above the center frequency of the auditory filter, rather like “pushing a swing at the right time” (p. 97), and that the amplification “maximum gain may be about 50 dB, but it is not the same for all levels” (p. 98). — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 561 (#exemplifies, via linked claim)

Categorization

• XREF: connects to: MOC efferent activation restores auditory nerve dynamic range in noise; Contralateral efferent inhibition of compression amplifies inter-aural level differences; The basilar membrane’s mechanics enable the inner ear’s frequency analysis (+3 more)

Related

• Outer hair cells sit where basilar membrane vibration is greatest (similarity 0.88)
• The olivo-cochlear efferent system accelerates recovery from calcium-induced sensitivity changes. (similarity 0.87)
• Brainstem efferent signals shorten the hearing Bounce (similarity 0.86)
• Calcium oscillations in outer hair cells drive the hearing Bounce (similarity 0.85)
• Outer hair cells respond better than inner hair cells to low-frequency sound (similarity 0.83)
• Low-frequency receptor potentials drive oscillating calcium levels that modulate cochlear-amplifier gain (similarity 0.82)
• Active outer hair cell processing boosts internal response levels by up to 40 dB (similarity 0.82)
• MOC efferents reflexively modulate cochlear gain via outer hair cells (similarity 0.81)
• Low-frequency after-effects on inner-ear gain are calcium-mediated and olivocochlear-modulable (similarity 0.81)
• Outer hair cells provide active frequency-selective amplification in the cochlea (similarity 0.81)
• Brain efferents can dynamically adjust cochlear gain during listening (similarity 0.81)
• Medial olivocochlear efferents actively modulate cochlear gain during binaural listening (similarity 0.80)
• Low-frequency sound triggers larger cochlear responses than comparable higher frequencies. (similarity 0.80)
• An acoustic reflex desensitizes the ear to protect cochlear hair cells (similarity 0.80)
• The Bounce is a metabolic calcium effect, not mechanical damage to hair cells (similarity 0.80)

Broader Connections

• The basilar membrane’s mechanics enable the inner ear’s frequency analysis #expands (0.72)
• Outer hair cells sit where basilar membrane vibration is greatest #exemplifies (0.72) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 561
• The olivo-cochlear efferent system accelerates recovery from calcium-induced sensitivity changes. #expands (0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3744
• Contralateral efferent inhibition of compression amplifies inter-aural level differences #complicates (0.70)
• Each basilar membrane location acts as a bandpass filter tuned to a center frequency #complicates (0.70) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 595